Several techniques utilized to recover hydrocarbons in the form of bitumen from oil sands rely on generated steam to heat and lower viscosity of the hydrocarbons when the steam is injected into the oil sands. One common approach for this type of recovery includes steam assisted gravity drainage (SAGD). The hydrocarbons once heated become mobile enough for production along with the condensed steam, which is then recovered and recycled.
Costs associated with building a complex, large, sophisticated facility to process water and generate steam contributes to economic challenges of oil sands production operations. Once through steam generators (OTSGs) often produce the steam. Even with extensive water treatment, fouling issues persist and are dealt with through mechanical cleaning of boiler tubes, which increases operating costs and results in a loss of steam production capacity that translates to an equivalent reduction in production.
Chemical additives introduced into the water provide one option for the treatment. For example, some known boiler anticorrosion compounds function by scavenging oxygen. Agents for only oxygen scavenging provide no added benefit if used in excess since dissolved oxygen removal fails to mitigate other fouling issues.
Therefore, a need exists for methods and systems for limiting organic fouling while generating steam from water that may be recycled in thermal oil recovery processes.